Apparatuses for blow moulding plastic performs into plastic containers have been known from the prior art for a long time. It is specifically known here to apply a gaseous medium and in particular pressurised air to the plastic preforms, in order to expand them in this way into plastic containers within a blow mould. During these blow moulding processes, different pressure levels are used, such as for example a preblow pressure and a main blow pressure and the like. Therefore, several valves which control the pressurised air supply to the container are required, in order to apply the individual pressure levels to the plastic containers.
WO2006/096460 A1 describes a blow air control system. This blow air control system controls the injection of a first gas under a first pressure into the inside of a plastic preform and subsequently the injection of a second gas under a second pressure, which is higher than the first pressure, into the inside of the plastic preform.
WO2007/107016 A1 describes a blow station for a stretch blow moulding machine. Here, a rotary distributor for compressed air and a plurality of blow moulding stations are provided, which are radially arranged about a rotary axis of the distributor. In each station, individual valves are arranged in a single blow moulding block which is disposed laterally on a blow cylinder.
A valve assembly for cavity blow moulding machines and a method for blowing are known from WO2008/040388 A1. Here, too, a preblow valve and a main blow valve are provided, in order to generate a blow volume at different pressure levels. Here, the preblow valve and the main blow valve are arranged to act in parallel relative to each other and the preblow valve is implemented as a multi-way valve, with the first inlet line having a throttle and a check valve acting against the supply direction.
U.S. 2008/0213423 A1 describes a fluid flow control assembly for a container blow moulding machine. Here, all of the individual valves are arranged on the front surface of a housing for a blow nozzle.
From DE 199 38 724 A1, an apparatus for producing plastic containers by means of stretch blow moulding is known. Here, a container to be produced is held by its open end by means of a receptacle, and this receptacle can be brought into engagement at the end thereof which faces away from the container with a distributor block in a fluid-tight manner, and the stretch plug is guided through the distributor block in an actual extension of this receptacle in a movable manner.
During the manufacture or construction of such systems efforts are always made to keep the necessary energy expenditure for running the systems as low as possible. The valve blocks for such apparatus usually have an air connection plate, an air distribution plate, a control block, blow valves, a blow piston as well as a connection for a silencer as well as a blow slide. As a result of the design known from the prior art, usually so-called dead volumes are formed here, in particular downstream of the valves, which means in the blow chamber or in the supply line to the blow chamber. These dead volumes are detrimental to the operation of such an apparatus, since they would first have to be filled with pressurised air, before the actual moulding process can be carried out.
It may therefore be desirable to design an apparatus for moulding plastic containers to be more energy efficient. For example, the above-mentioned dead volumes for the blow air may be reduced. Further, it may be desirable to realize reproducible blow moulding processes, in particular from one blow station to another blow station.